That is so bizarre and backwards! A meat-eater could eat anything at a vegetarian restaurant, but the converse is so not true, it isn’t even funny.
I’m not vegetarian, but I often choose vegetarian food. My family and I went to eat at a Cracker Barrel, and I happily ordered the beans and greens from their side dish section, and they also happened to have brown rice. I was pleasantly surprised that they offered such wholesome vegetarian fare, and quite proud of myself for choosing a healthy meal instead of one the many tasty-looking entrees that were loaded with saturated fat. Except that, when my beans and greens arrived, I discovered that both were cooked with ham hocks. (I probably should have guessed!) The brown rice also tasted like there was maybe a chicken boullion cube or something thrown in. I wondered if there was anything on the menu that a vegetarian could eat.
Why it would be such a terrible hardship for a non-vegetarian to have a healthy, delicious meal that doesn’t have meat in it, I do not understand–though I encountered this problem as well my in-laws came to town and I suggested that we go to an excellent (indeed, famous) vegetarian restaurant. I told them ahead of time that it was vegetarian, and asked if that was alright, and they said it was my birthday, and we could go anywhere I wanted. But when we got there, they were dissatisfied with the choices (they thought, what, that this was the sort of vegetarian restaurant that served just a little meat?) and again, I said we could go somewhere else, but my MIL insisted (quite obviously against the feelings of the rest of the party) that it was my birthday, and we should eat at the restaurant of my choosing. So I had a delightful whole-grain stew and enjoyed the uncomfortable company of my sullen, meat-deprived inlaws. sigh
It’s very kind of you to let people bring meat to your dinner, Otto. Not everybody likes tofurkey, and it’s nice of you to be willing to compromise. I think it’s also very nice of you to go to all the trouble of cooking! I’m sure your family will appreciate your extra effort.
The prayer thing is tough. Perhaps you could just have said, up front, to avoid a confrontation at dinner, that you will not be participating if they choose to have a prayer. Anyway, your house, your grub, you get to decide–and I agree that it’s best to make it clear to your guests ahead of time. (I like Rilch’s suggestion, too.)
Good luck! I hope your father’s good will holds out, and that everything goes smoothly.